Atlas CZ 21” cars Issues on O72 switches, on my layout.

For what it's worth, I found out the hard way that those types of 21" long passenger cars do NOT like too close together turnouts into curves, i.e. the "S curve syndrome".

I note that you have Ross Custom switches.  After consulting with Atlas about the problem, perhaps Steve Brenneisen from Ross might make a suggestion.  It sure makes a pretty looking train, whatever you do!

Paul Fischer

Interesting, I don't run mine across any switches. I use atlas track and will have to investigate now.

I have the complete car set as well. The cars are beautiful, however they are not made to work on 072 curves or switches. 

When the cars where first released I had no issue with ONE car taking these turns but couple another on and the fun began.

First off I have notice that the details of the underbody do not like DZ1000 switch machines and their large screw heads. They even seem to pick the switch springs.

I have never been able to get this set to traverse over 072 curves. Thus I only run them on my upper deck with a minimum of 096, and I still have issues. I have adjusted the draw bars and removed the air hose details, however this lead to other issues.

Mostly unwanted uncoupling.  S curves are a curse, even on 096 the trucks and couplers will uncouple, and the inside of the trucks hit the car bodies and will cause a derailment. 

I use the same electrical tape fix for droopy coupler tacks.

The dome cars seem to be my most aggravation.  If you do find a fix, I will be listening. However, grinding away details, which I did not want to do, may be our only hope.

Buzz

You might want to ask guys over on the "3RS" forum about the Kadee conversions. I'm sure someone over there has done these cars by now.

From your photos, it looks like the cars are pre-drilled for the draft gear boxes as is usual for Atlas equipment. You probably just need some styrene shims and Kadees with the correct shank length. 

That's a nice layout you've got started there. Good luck!

I have the same consist that you have,I put tape on all of the thumb tacks before the cars ever saw track.I run on 096 curves and Ross 096,096x072 switches as well as 096 curve switches with no problems,I also back the cars into the passenger platform thru the switches with no problem going slowly.

Mikey

I don't have this set.  You might try raising the car body height by putting washers between the trucks and the frame to allow the trucks to just clear the bottom of the car body when they swing.  This shouldn't change the coupler heights since the couplers are attached to the trucks.  I have no idea if this would be an easy or difficult modification.   I have done this successfully on a couple of my cars that had similar problems.

NH Joe

I believe I have made some progress since I first wrote the original post involving the O72 issues with the Atlas CZ cars and O72 switches. I appreciate the post replies and emails that offered suggestions and ideas. I have some conclusions that I have applied to my layout and cars. It is not perfect yet, but improved. I will share what I’ve have found to date, my actions taken and why. I found a variety of issues that varied from car to car. I think that these issues mostly appear when trying to use O72 curves and switches and probably become insignificant with larger radii.

 1 Removal of air brake lines and steam pipes. Bending foot grab irons

The pipes hit the frame of the car, being one of the limitation of the truck rotation. They come off fairly easily, many of them are already off and in the box when you get them. The brake line comes off easily with the trucks still mounted but steam pipes need to have the coupler removed which means you also need the adjustable bracket removed. The steam line is more fragile than the break line and needs to be removed carefully. A miniature thin blade screw driver can be used to pry a little bit at a time on each side of the connection. It can be removed with out damage if done patiently and gradually. It is held in by a mortise on the coupler and tenon on the steam pipe. After removal of the pipes reassess whether the foot step grab iron interfere with the rotation of the truck. If they do, leave alone until you have finalized the height of the coupler, then if needed they can be bent up slightly with the needle nose pliers. This is much easier than reshaping or remaking new.

 2  Centering spring stability

I found that on about 1/3 of my cars that the coupler centering spring was moving off the small dimple and post that is used to hold it in place. The spring is then resistant to re-centering the coupler after if moves off the post. It can be observed when exercising the coupler, that the spring will rotate. The spring can be stabilized sometimes by adjusting the tightness of the holding screw securing the coupler mounting (see #3). On the springs that couldn’t be stabilized with adjustment I used Mike’s CA Glue to hold it in place. Some of the posts showed wear. This is a very delicate procedure. No glue can remain on the surface of the spring that bears the coupler, the hole that acts as the bushing, or on the leaf springs. The leafs must be able to act as springs. I feel that if you are doing this you need to use scopes and head lights. I doubt that Atlas would approve this and might void your warranty

Box Spring

Post and Dimple Worn

Seated well and Glued

Seated well

Not seated well and will not work

3  Adjustment of coupler on the adjustable bar.

The cars I have, required that I adjusted the tightness of everyone of the attachment screw. About ½ were loose and dropping or were too tight to swing properly. If couplers are dropping they are also letting the spring become non-functional. It is a fine adjustment, similar to tightening a bearing or bushing on a car or bicycle wheel. My method was to remove the screw holding the release lever and then tighten the screw holding the coupler until it is fully seat and the coupler doesn’t swing. Then back off 1/8 to 1/4 turn. Check if it snaps back right and left and doesn’t have vertical slop. Most of my cars had a washer between the head and the adjustable bar, but a significant number didn’t have them. I believe the system is that the mounting screw is set then fixed when you tighten the screw that holds the coil spring and release lever. They should meet inside their common shaft although they are not the same gauge. You can over tighten the lever screw. I had 4 mounting screws that were bent. Two of which the heads twisted off when I tried to removed them. Initially I had thought they were bent from the thumb tack hitting parts of the switch, but I now believe it was from the manufacture over tightening the larger lever screw. I had also linked the bend I saw in the lever arm to the same cause (striking a switch part), but since most of the arms have a slight bend, I think it was from the hole punching process during manufacturing. I have set all of the coupler heights to ¾” + or - 1/32 from the top of the coupler knuckle to the top of the middle rail. The adjustment if needed is easily done with the 2 back mounting screw. Very few of the couplers needed this after tightening the coupler properly to the adjustment bar. If you need pictures or additional clarity with the adjustments, please email me.

 4  Adjusting the rollers or the O72 Switch

After all the adjustment were done, I still have significant derailing on the switches. The 21 CZ’s are extremely difficult to see what is happening when they go over a switch, but you can feel the binding some times with the right pressure on the car. I knew there is some problem between the truck and the switch. I took videos to help see the problem. I do not have any extra trucks but I do have extra cars. I removed the trucks form one of my cars. By doing so I could see the problem and cause, I believed. I can only say this is the cause on the Ross switches but I would think it would pertain to all the manufactures that have sharp rails versus tubular rails. My belief is that Atlas has used a roller that really has sharp edges (a true cylinder) compared to other rollers that have a chamfered edge like a salami shape. I have taken pictures I hope you can make out. The roller rolls in and drops down off the entrance center rail over the outside rail and onto another guard rail (which is lower) then needs to rise up to the exit center rail. The sharp edges prevent the roller from consistently rolling up on the exit center rail and when it doesn’t it causes a derailment. I believe the solution is to modify the roller or the switch. I will probably be doing both. The red tape on the switch picture is the area where the square edge roller hits the exiting middle (3^rd) rail and binds. Without the body on the trucks it is very easy to see the problem, and make it reoccur in the testing. My solution is to regrind the edges of the rollers and place an elevating filler between the guard rail and the middle rail. The roller can be placed securely in a drill and the edges rounded by a fine file. I am concerned about removing and the replacing the roller and what affect it would have on the bracket. I do not know if Atlas would agree.

Sharp Edge Roller

Red Tape Contact Point of Sharp Roller

Red Tape Contact Point of Sharp Roller

Path of Roller  Middle rail to outside rail to lower guard rail to higher exit middle rail.

Red tape and contact of leading edge of sharp roller causing derailment not allowing truck to follow track but forcing it to the right because it can't lift up to the rail

I will report back when that is done, the filler and grinding.

Thanks for following 

Buzz

Photos Updated, note the roller below rail. Hope this makes it easier to see.

Buzz

I took my 13 amtrak cars to nj hirailers and had a complete meltdown, derailed every chance it could through switches and there O72 curves. The plastic diaframs fell off too, the cars have no problems at home on my circle of O82 realtraxx.

Buzz - thank you for the diligent work. I appreciate the updates and I will be following your findings, I have sentence my CZ cars to run an outer loop with 096 min curves, with no cross over switches.

I was able to eliminate the un-coupling of cars by adding a small piece of black electrical tape to the inside of the couplers.  

Great write up. Now I know why postwar Lionel had chamfered rollers.

Try calling Atlas and see if you can get chamfered rollers.

j Daddy.  That is a great suggestion and easy to do.  I was going to use some other material like Lighting powder and CA glue. I will use your tape method. Most of my couplers are 15/64 to 14/64 a few (2) were 13/64. It doesn't take much of a shim to correct the problem.

Thanks Again,

Buzz

 I'm a firm believer in Kadee couplers. It looks like the coupler mounts are the same as the scale coupler conversion they were offering in freight cars at one time. Despite their issues they got me started in converting everything to Kadee's. In your case these might be worth a shot and give the Atlas adjustacouplers a try.  I would first remove the the stock Atlas centering spring and replace it with a Kadee which is much softer. You can also file  back the coupler box to allow more swing. With this setup the couplers will actually stretch out a bit as the cars start to move. With truck mounted couplers and couplers that can move more freely you should be able to adjust the length and get it working reliably. You want have issues with a thumbtack hitting the rails. 

 If you are going to run this as a consist without doing switching moves you should be fine. A little care needs to be taken when backing up. You will need to leave the stock 3 rail coupler in place on the head end car to mate with the engine.

 If you want to try this setup. I can send you some couplers and Kadee springs.

I'll second Dave C's post above. Although I did not purchase the Atlas CZ passenger set, I did purchase the dome observation and baggage car. I found a way to modify the Atlas "claw coupler" mount, in order to accept a Kadee O Scale coupler, and still retain that "talgo truck mounting" arrangement that Atlas uses. I now can include that really nice CZ baggage car into my CB&Q heavyweight passenger train from Golden Gate Depot.

I have removed the thumbtack from several cars. How often does one uncouple passenger cars anyway? The uncoupling tab can be removed from the coupler and the top pf the thumbtack drilled out. Reassembly leaves a coupler without a thumbtack at all. Works well even if it droops a little.

Dave C do you have any photos of the installation of the Kadee Couplers on the CZ cars you could share. I would like to try a couple of them. I would also like to see what the 2R Atlas CZ's look like from someone who bought them to see how they were set up.

I don't own the CZ cars. Just speaking from experience of doing many scale coupler conversions on a variety of cars. I never had any issues with the Atlas adjustacouplers. My biggest gripes was they wouldn't mate to a stock 3 rail coupler, the centering spring was way to stiff, and they wouldn't work with the Kadee magnets. I have a few sets of these couplers and would be happy to swap them out to a Kadee spring and ship them to you to try. This would eliminate your thumbtack issue. Atlas looks like they tried to solve the age old problem of offering both 3 rail and scale couplers on the same model truck. Seems the 3 railers got the quick fix were as the scale guys simply body mount a coupler or use the scale coupler and box that fits the 3 rail mount.

 If you decide on using Kadee's. You will need to fabricate your own mounts. It seems like you could bolt a piece of brass or aluminum stock to the Atlas bracket. Then drill mounting holes to attach the Kadee box and coupler. A lot of work for a fleet of cars.